Conventional ovens and similar systems for heating an inedible object, for instance a thermoplastic preform intended for the manufacture of a container, are provided with a plurality of radiating lamps each provided with an optical reflector. The radiating lamps are typically linearly elongated infrared bulbs. Each bulb is arranged substantially horizontally and retained in position by clips or similar fixing elements which both hold the bulb at a desired position. The bulbs are also connected to a source of electrical power through such clips.
U.S. Pat. No. 5,549,468 discloses a construction of a heating lamp assembly with adjustably positionable clips for holding IR lamps and reflectors in stainless steel material arranged back to the lamps to direct the IR beams onto the preform. The reflectors each have a length approximating the length of the lamps and have an arcuate extent of about 200°. The preform is placed in a preform oven between two lateral walls facing each other, one of which includes the heating lamp assembly. The lamps are placed through adjustment of the positionable clips one above another so as to face the body of the preform.
In a known manner, the preform is heated on the move, its neck facing downward. Each preform is rotated about itself, around a vertical axis, so that the lamps radiate to the whole periphery of the preform body. The bottom of the oven is provided with protective means designed to form a heat shield capable of protecting the neck of the preform and of preventing it from deforming. The height of the heating lamp assembly is chosen in relation to the length of the body of the preform.
Thermoplastic container manufacturers presently seek to reduce as far as possible the inherent costs/charges associated with the operation of the machines for manufacturing these containers, and especially the consumption of electrical energy by these machines. Now, the preform-heating oven consumes most of the electrical energy in an installation for manufacturing thermoplastic containers. Consequently, any reduction, albeit a small one, in losses in the oven is reflected by an appreciable concomitant reduction in the consumption of electrical energy, and therefore in a financial saving and better profitability of the machine.